Step 1

Separate the egg and place the egg yolk in a small saucepot. The whites can be saved for a different recipe.

Step 2

Add the water and lemon juice to the pot with the yolk and whisk until smooth (no heat yet).

Step 3

Cut the butter into small pieces (about ¼ Tbsp size) , then add them to the saucepot with the egg yolk, lemon, and water.

Step 4

Place the pot over medium-low heat. Continuously whisk as the mixture heats. First the butter will melt, then the mixture will begin to get a bit frothy. Finally, as the egg yolk begins to cook, the sauce will thicken. Make sure you're whisking the entire time to achieve a light, smooth sauce. Once it thickens to the consistency of gravy, remove the pot from the heat.

Step 5

Season the sauce with salt and cayenne, then drizzle the sauce over your favorite food!